This invention relates to an expandable and collapsible insulated food delivery bag commonly used for delivering food products such as a hot pizza within a paperboard box and of the general type disclosed in U.S. Pat. No. 6,512,211 which issued to the assignee of the present invention. In the insulated bag or pouch disclosed in this patent, a heating element is carried by the bottom wall of the bag for maintaining the temperature of a hot food product or pizza. Other forms of heated food or pizza delivery bags are disclosed in U.S. Pat. Nos. 6,060,696, 6,248,981 and 6,281,477. The bags disclosed in these patents are made to receive one or more boxes enclosing pizzas and also carry heating elements.
It is also known to construct a box-like pizza delivery bag for delivering multiple paperboard pizza boxes and in which rigid top, bottom and side walls of the box-like bag are provided with removable vacuum insulation panels. The rigid bag may also incorporate a heating element or hot packs for maintaining the heated temperature of the multiple pizza boxes within the bag. Such a bag has been manufactured and marketed by AcuTemp in Dayton, Ohio and sold under the trademark ThermoPocket. This company also owns U.S. Pat. No. 6,192,703 which discloses a box-like insulated container having vacuum insulated panels for delivering temperature-sensitive materials including food products such as pizza. The container may also incorporate a refrigeration unit for maintaining the temperature-sensitive material at a substantially constant temperature during shipment.